A packaged electronic device has first and second lead frame leads and a passive electronic component mounted, across a gap between the leads, on the top sides of the leads, using an adhesive. Facing lateral sides of the leads each include a recess that receives the adhesive. The recess promotes adhesion between the electronic component and the corresponding lead while limiting spread of the adhesive on the bottom side of the electronic component. The adhesive in the recesses promotes adhesion of the component to the leads by inhibiting cracking, and enhances inspection capability at the device backside.
Legal claims defining the scope of protection. Each claim is shown in both the original legal language and a plain English translation.
1. A sub-assembly for a packaged electronic device, the sub-assembly comprising: a first lead of a lead frame, the first lead comprising a top side, a bottom side, and a first lateral side; a second lead of the lead frame separated from the first lead by a gap, the second lead comprising a top side, a bottom side, and a first lateral side; and an electronic component comprising a top side, a bottom side, and first and second lateral sides, wherein the electronic component is mounted, across the gap, onto the top sides of the first and second leads using an adhesive, wherein each first lateral side of the first and second leads defines a recess that receives the adhesive to promote adhesion between the electronic component and the corresponding lead while limiting spread of the adhesive on the bottom side of the electronic component.
A sub-assembly for a packaged electronic device has a first lead and a second lead separated by a gap. An electronic component (like a resistor or capacitor) is mounted across this gap, on top of the leads, using adhesive. Each lead has a recess on its side facing the gap. This recess holds the adhesive, improving the bond between the component and the lead while preventing the adhesive from spreading too far underneath the component.
2. The sub-assembly of claim 1 , wherein: a first portion of the adhesive is located between the bottom side of the electronic component and the top side of the first lead; a second portion of the adhesive is located between the bottom side of the electronic component and the top side of the second lead; a third portion of the adhesive spans between the bottom side of the electronic component and the first lateral side of the first lead; and a fourth portion of the adhesive spans between the bottom side of the electronic component and the first lateral side of the second lead.
In the sub-assembly where an electronic component is mounted on leads with adhesive-filled recesses, there are specific adhesive locations. A first part of the adhesive is between the component's bottom and the first lead's top. A second part is between the component's bottom and the second lead's top. A third part spans from the component's bottom to the recess on the first lead's side. A fourth part spans from the component's bottom to the recess on the second lead's side.
3. The sub-assembly of claim 2 , wherein the third and fourth portions of the adhesive correspond to adhesive meniscus.
In the sub-assembly with adhesive between the electronic component and leads, and adhesive spanning between the component's bottom and the lead recesses, the adhesive portions connecting the component's bottom to the lead recesses form a meniscus shape (curved surface). This shape is naturally created by the surface tension of the adhesive.
4. The sub-assembly of claim 2 , wherein the third and fourth portions of the adhesive are visible from below the sub-assembly.
In the sub-assembly with adhesive between the electronic component and leads, and adhesive spanning between the component's bottom and the lead recesses, the adhesive portions connecting the component's bottom to the lead recesses are visible when looking at the sub-assembly from below. This allows for visual inspection of the adhesive joint.
5. The sub-assembly of claim 2 , wherein: a fifth portion of the adhesive spans between the first lateral side of the electronic component and the top side of the first lead; and a sixth portion of the adhesive spans between the second lateral side of the electronic component and the top side of the second lead.
In the sub-assembly where an electronic component is mounted on leads with adhesive-filled recesses, and adhesive connects the component's bottom to the lead recesses, there are additional adhesive locations. A fifth portion spans from the side of the electronic component to the top of the first lead, and a sixth portion spans from the side of the electronic component to the top of the second lead.
6. The sub-assembly of claim 5 , wherein the fifth and sixth portions of the adhesive correspond to adhesive meniscus.
In the sub-assembly with adhesive between the electronic component and leads, adhesive spanning between the component's bottom and lead recesses, and adhesive portions connecting the component's sides to the lead tops, the adhesive portions connecting the component's sides to the lead tops form a meniscus shape.
7. The sub-assembly of claim 5 , wherein the fifth and sixth portions of the adhesive are visible from above the sub-assembly.
In the sub-assembly with adhesive between the electronic component and leads, adhesive spanning between the component's bottom and lead recesses, and adhesive portions connecting the component's sides to the lead tops, the adhesive portions connecting the component's sides to the lead tops are visible when looking at the sub-assembly from above, allowing for visual inspection.
8. The sub-assembly of claim 1 , wherein the electronic component comprises a passive electronic device.
In the sub-assembly where an electronic component is mounted on leads with adhesive-filled recesses, the electronic component is a passive device like a resistor, capacitor, or inductor.
9. The sub-assembly of claim 1 , wherein the adhesive comprises epoxy.
In the sub-assembly where an electronic component is mounted on leads with adhesive-filled recesses, the adhesive used is epoxy.
10. The sub-assembly of claim 1 , wherein the adhesive comprises solder.
In the sub-assembly where an electronic component is mounted on leads with adhesive-filled recesses, the adhesive used is solder.
11. The packaged electronic device of claim 1 .
This is a packaged electronic device featuring a sub-assembly that has a first lead and a second lead separated by a gap. An electronic component (like a resistor or capacitor) is mounted across this gap, on top of the leads, using adhesive. Each lead has a recess on its side facing the gap. This recess holds the adhesive, improving the bond between the component and the lead while preventing the adhesive from spreading too far underneath the component.
12. The lead frame of claim 1 .
This concerns the lead frame that has a first lead and a second lead separated by a gap. An electronic component (like a resistor or capacitor) is mounted across this gap, on top of the leads, using adhesive. Each lead has a recess on its side facing the gap. This recess holds the adhesive, improving the bond between the component and the lead while preventing the adhesive from spreading too far underneath the component.
13. A method for assembling a sub-assembly for a packaged electronic device, the method comprising: providing a lead frame comprising (i) a first lead comprising a top side, a bottom side, and a first lateral side and (ii) a second lead separated from the first lead by a gap, the second lead comprising a top side, a bottom side, and a first lateral side; applying adhesive to the top sides of the first and second leads; and applying an electronic component comprising a top side, a bottom side, and first and second lateral sides onto the adhesive, wherein the electronic component is mounted, across the gap, onto the top sides of the first and second leads wherein each first lateral side of each of the first and second leads defines a recess that receives the adhesive to promote adhesion between the electronic component and the corresponding lead while limiting spreading of the adhesive on the bottom side of the electronic component.
A method for assembling a sub-assembly for a packaged electronic device involves providing a lead frame with two leads separated by a gap. Each lead has a top, bottom, and a side. Adhesive is applied to the top of each lead. An electronic component (with a top, bottom, and sides) is then placed onto the adhesive, bridging the gap between the leads. Each lead has a recess on its side that receives the adhesive, improving adhesion while limiting adhesive spread under the component.
14. The method of claim 13 , wherein: a first portion of the adhesive becomes located between the bottom side of the electronic component and the top side of the first lead; a second portion of the adhesive becomes located between the bottom side of the electronic component and the top side of the second lead; a third portion of the adhesive spans between the bottom side of the electronic component and the first lateral side of the first lead; and a fourth portion of the adhesive spans between the bottom side of the electronic component and the first lateral side of the second lead.
In the assembly method where an electronic component is mounted on leads with adhesive-filled recesses, specific adhesive locations are formed. A first adhesive portion is between the component's bottom and the first lead's top. A second is between the component's bottom and the second lead's top. A third spans from the component's bottom to the recess on the first lead's side. A fourth spans from the component's bottom to the recess on the second lead's side.
15. The method of claim 13 , wherein the third and fourth portions of the adhesive correspond to adhesive meniscus.
In the assembly method where an electronic component is mounted on leads with adhesive, and adhesive spans between the component's bottom and lead recesses, the adhesive portions connecting the component's bottom to the lead recesses form a meniscus shape due to surface tension.
16. The method of claim 13 , further comprising viewing the sub-assembly from below to verify existence of the third and fourth portions of the adhesive.
The assembly method where an electronic component is mounted on leads with adhesive, and adhesive spans between the component's bottom and the lead recesses, further includes visually inspecting the sub-assembly from below to check for the presence of the adhesive portions connecting the component's bottom to the lead recesses. This verifies proper adhesive application.
17. The method of claim 13 , wherein: a fifth portion of the adhesive spans between the first lateral side of the electronic component and the top side of the first lead; and a sixth portion of the adhesive spans between the second lateral side of the electronic component and the top side of the second lead.
In the assembly method where an electronic component is mounted on leads with adhesive-filled recesses, and adhesive connects the component's bottom to lead recesses, additional adhesive locations are created: a portion spans from the component's side to the top of the first lead, and another spans from the component's side to the top of the second lead.
18. The method of claim 17 , wherein the fifth and sixth portions of the adhesive correspond to adhesive meniscus.
In the assembly method with adhesive between the electronic component and leads, adhesive connecting the component's bottom to lead recesses, and adhesive portions connecting the component's sides to lead tops, the adhesive portions connecting the component's sides to the lead tops form a meniscus shape.
19. The method of claim 17 , further comprising viewing the sub-assembly from above to verify existence of the fifth and sixth portions of the adhesive.
The assembly method with adhesive between the electronic component and leads, adhesive connecting the component's bottom to lead recesses, and adhesive portions connecting the component's sides to lead tops, includes visually inspecting the sub-assembly from above to check for the presence of the adhesive portions connecting the component's sides to the lead tops, verifying proper adhesive application.
20. The method of claim 13 , wherein the electronic component comprises a passive electronic device.
In the assembly method where an electronic component is mounted on leads with adhesive-filled recesses, the electronic component used is a passive device like a resistor, capacitor, or inductor.
21. A packaged electronic device assembled using the method of claim 13 .
This packaged electronic device is created using the assembly method of providing leads, applying adhesive, mounting an electronic component, and using recesses in the leads to improve adhesion, therefore the device benefits from improved adhesion and limited adhesive spread.
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December 7, 2016
August 1, 2017
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